linux-kernel - Re: [PATCH v1] riscv/kexec_file: Fix relocation type R_RISCV_ADD16 and R_RISCV

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20240711145330.6625c200@mordecai.tesarici.cz>
Date: Thu, 11 Jul 2024 14:53:30 +0200
From: Petr Tesařík <petr@...arici.cz>
To: sunying@...c.iscas.ac.cn
Cc: ebiederm@...ssion.com, paul.walmsley@...ive.com, palmer@...belt.com,
 aou@...s.berkeley.edu, kexec@...ts.infradead.org,
 linux-riscv@...ts.infradead.org, linux-kernel@...r.kernel.org,
 zhuhengbo@...as.ac.cn
Subject: Re: [PATCH v1] riscv/kexec_file: Fix relocation type R_RISCV_ADD16
 and R_RISCV_SUB16 unknown

On Thu, 11 Jul 2024 08:32:36 +0000
sunying@...c.iscas.ac.cn wrote:

> From: Ying Sun <sunying@...c.iscas.ac.cn>
> 
> Runs on the kernel with CONFIG_RISCV_ALTERNATIVE enabled:
>   kexec -sl vmlinux
> 
> Error:
>   kexec_image: Unknown rela relocation: 34
>   kexec_image: Error loading purgatory ret=-8
> and
>   kexec_image: Unknown rela relocation: 38
>   kexec_image: Error loading purgatory ret=-8
> 
> The purgatory code uses the 16-bit addition and subtraction relocation
> type, but not handled, resulting in kexec_file_load failure.
> So add handle to arch_kexec_apply_relocations_add().
> 
> Tested on RISC-V64 Qemu-virt, issue fixed.
> 
> Co-developed-by: Petr Tesarik <petr@...arici.cz>
> Signed-off-by: Petr Tesarik <petr@...arici.cz>

Let me confirm I have seen this, and it is correct.

Petr T

> Signed-off-by: Ying Sun <sunying@...c.iscas.ac.cn>
> ---
>  arch/riscv/kernel/elf_kexec.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/arch/riscv/kernel/elf_kexec.c b/arch/riscv/kernel/elf_kexec.c
> index 11c0d2e0becf..3c37661801f9 100644
> --- a/arch/riscv/kernel/elf_kexec.c
> +++ b/arch/riscv/kernel/elf_kexec.c
> @@ -451,6 +451,12 @@ int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
>  			*(u32 *)loc = CLEAN_IMM(CJTYPE, *(u32 *)loc) |
>  				 ENCODE_CJTYPE_IMM(val - addr);
>  			break;
> +		case R_RISCV_ADD16:
> +			*(u16 *)loc += val;
> +			break;
> +		case R_RISCV_SUB16:
> +			*(u16 *)loc -= val;
> +			break;
>  		case R_RISCV_ADD32:
>  			*(u32 *)loc += val;
>  			break;